Amateur radio (also called ham radio) describes the use of radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communication.

Name: British Tungsram Radio Works Ltd. (GB) Abbreviation: britishtun Products: Tube manufacturer
Summary: British Tungsram Radio Works Ltd. See Tyne page 466. The same
tube/valve made in Hungary can have an other designation in GB. Founded: 1928 Closed: 1952 Production: 1928 - 1952
History: The Hungarian Company established a factory in England in
1928. There were some 43 different types available by 1932. Specialising
in equivalents of the USA range it was ahead of Brimar and other UK
companies. It was taken over by Philips in 1952 and continued to manufacture at the factory until 1956.